Back to EveryPatent.com
United States Patent |
5,722,131
|
Leistner
,   et al.
|
March 3, 1998
|
Clip for furniture springs, and method of manufacture
Abstract
A furniture clip of the type used with furniture springs, having wire
frames, and in which such furniture clips furniture clips are used for
attaching the wire frames to furniture, and having a sheet metal member
defining length and width, and formed transversely with a wire receiving
recess, and two panels extending at an acute angle relative to one another
on either side of the recess, a shield of flexible thermoplastic material
extending over the inner surfaces of the two panels, and extending around
said wire recess, and edge portions of the thermoplastic defining a width
greater than the width of the sheet metal.
Inventors:
|
Leistner; Volkmar W. (Toronto, CA);
Olson; Garry Randall (Scarborough, CA)
|
Assignee:
|
Sigma Tool & Machine (Scarborough, CA)
|
Appl. No.:
|
506558 |
Filed:
|
July 25, 1995 |
Current U.S. Class: |
24/703.1; 403/188 |
Intern'l Class: |
A47C 023/00 |
Field of Search: |
24/703.1
5/259.1,263,264.1
267/99,110
403/393,270,188
248/60,71,74.3
|
References Cited
U.S. Patent Documents
2936982 | May., 1960 | Cushenberry.
| |
2982505 | May., 1961 | Shy.
| |
3159708 | Dec., 1964 | Deal | 403/188.
|
3199163 | Aug., 1965 | Surletta | 5/259.
|
3422468 | Jan., 1969 | Schutz | 5/259.
|
4318518 | Mar., 1982 | Davis | 248/60.
|
Primary Examiner: Brittain; James R.
Claims
What is claimed is:
1. A furniture clip of the type used in association with furniture spring
assemblies for furniture, having wire springs, and in which such furniture
clips are used, for attaching such wire springs to said furniture said
furniture clip comprising;
a sheet metal panel defining length and width, and formed transversely to
define a wire receiving recess;
two sheet metal panel portions defined by said panel extending at an acute
angle relative to one another on either side of said wire receiving
recess, said sides of said panel portions adjacent said recess defining
inner surfaces of said panel portions, and outer surfaces of said panel
portions on the opposite sides thereof;
two pairs of openings of elongated shape formed through respective said
sheet metal panel portions, said openings in each said pair being arranged
parallel to one another and respective pairs registering with one another
with said elongated openings in registration with one another;
a shield of flexible thermoplastic material extending over said inner
surface portions of said two panel portions, and extending around said
wire receiving recess;
two pairs of openings of elongated shape formed through said shield of
thermoplastice material, said openings in each said pair being arranged
parallel to one another and said openings in respective pairs registering
with respective pairs of openings in respective said sheet metal panel
portions;
edge portions of said thermoplastic shield extending along either edge
thereof, and defining a width greater than the width of said panel
portions, and,
retaining means retaining said thermoplastic shield in position on said
sheet metal panel.
2. A furniture clip as claimed in claim 1 wherein said retaining means
comprise retaining portions extending substantially parallel to one
another and adapted to overlay edge portions of said outer surfaces of
said metal panel portions.
3. A furniture clip as claimed in claim 2 including wedging surfaces on
said retaining portions, to facilitate spreading of said retaining
portions, for attachment to said metal panels.
4. A furniture clip as claimed in claim 1 and wherein said retaining means
comprises a bonding layer between said shield and said sheet metal panel,
bonding the two together.
5. A furniture clip as claimed in claim 4 and wherein said shield is of
generally channel-shaped cross-section, and defines a central planar
portion overlying the inside surfaces of said sheet metal panel portions,
and edge wall portions extending around respective edges of said panel
portions.
6. A furniture clip as claimed in claim 1 and wherein said shield defines
edge walls, having inwardly angled retaining surfaces adapted to
interengage with edge portions of said sheet metal panel portions.
7. A furniture clip of the type used in association with furniture spring
assemblies for furniture, having wire springs, and in which such furniture
clips are used, for attaching such wire springs to said furniture said
furniture clip comprising;
a sheet metal panel defining length and width, and formed transversely to
define a wire receiving recess, and two panel portions extending at an
acute angle relative to one another on either side of said wire receiving
recess, said sides of said panel portions adjacent said recess defining
inner surfaces of said panel portions, and outer surfaces of said panel
portions on the opposite sides thereof; and,
a shield of flexible thermoplastic material extending over said inner
surface portions of said two panel portions, and extending around said
wire receiving recess, said thermoplastic shield comprising two separate
shield portions, said shield portions being fitted around said metal
strip, from opposite edges thereof, and said two shield portions each
defining at least one side portion adapted to interengage and be bonded to
a respective side portion of the other said shield, whereby to secure said
shield on said metal strip.
8. A furniture clip as claimed in claim 7 wherein said thermoplastic shield
portions are generally elongated U-shaped in section.
9. A furniture clip as claimed in claim 7 wherein said thermoplastic shield
portions define at least one bonding edge, said bonding edge being tapered
whereby to overlap and interengage with adjacent bonding edge of an
adjacent said shield portion.
10. A furniture clip as claimed in claim 7 wherein said shield portions
define a generally J-shape in section, with the longer portion of said
J-section being adapted to abut against the longer portion of the
J-section and an adjacent said shield portion, and the shorter portions of
said shield portions being adapted to wrap around the edges of said sheet
metal panel.
11. A furniture clip as claimed in claim 10 wherein said longer portions of
said J-sections define reduced thickness sections, which are adapted to
overlap one another, and to be bonded to one another thereby securing said
two portions of thermoplastic shield around said metal strip.
Description
FIELD OF THE INVENTION
The inventions relates to clips for securing furniture springs, which are
resistant to unwanted frictional sounds.
BACKGROUND OF THE INVENTION
The manufacture of furniture, particularly seating, chairs, couches and the
like, is usually based on a rigid wooden frame, and a spring assembly
supported by the frame.
The edges of the spring assembly are secured to the rigid frame by means of
furniture clips.
The same general arrangement is also sometimes used in other furniture such
as bedsprings and the like.
One of the problems in such furniture is that when the springs flex
consequently the spring wire will tend to flex within the clips securing
it to the frame. The wire, where it passes through each clip, presents a
metal to metal contact, which is usually under substantial tension.
Consequently any relative movement will tend to produce frictional sound
of some kind, resulting from the friction between the metals.
This situation has lead the industry to look for solutions to the problem.
One process has to use a solid plastic clip, However this is expensive and
has insufficient strength.
Another process has been to provide an adhesively bonded paper layer on the
inside surface of the clip. This solution is less expensive. However, the
clips treated in this way do not solve the problem for any great length of
time.
Another process uses plastic film laminated to paper. This is an
improvement, but is still not totally satisfactory.
Clearly there exists a need for some form of friction reducing means to be
applied to such furniture clips.
In seeking out such a solution to the problem however, it must be
recognized that a critical area of friction, which creates the problem,
besides the linear contact within the clip, is the area at the two corners
or edges of the clip. It is at these two corners or edges that the wire
enters, and leaves, the grip of the clip. These are therefore, the areas
of the maximum frictional contact, and maximum pressure. Any worthwhile
solution therefore, must direct itself at least in part to the problem of
limiting the metal to metal contact at these two points.
BRIEF SUMMARY OF THE INVENTION
With a view therefore to providing an improved solution to these problems,
the invention comprises a furniture clip of the type used in association
with furniture spring assemblies, having wire springs, and in which such
furniture clips are used, for attaching such wire springs, said furniture
clip comprising, a panel of sheet metal defining length and width, and
formed transversely to define a wire receiving recess, and two panel
portions extending at an acute angle relative to one another an opposite
sides of said wire receiving recess, said panel portion defining inner
surfaces of said panel portions facing one another, and outer surfaces of
said panel portions on the opposite sides thereof, defining outer surface
portions of said panel portions, a shield of thermoplastic material
extending over said inner surfaces of said two panel portions, and
extending around said wire recess, edge portions of said thermoplastic
shield extending along either edge said panel portions, and defining a
width greater than the width of said panel portions, and, retaining
portions on said thermoplastic shield, said retaining portions extending
substantially parallel to but spaced from said edges of said panel
portions, and adapted to engage edge portions of said outer surfaces of
said metal panel portions, thereby retaining said thermoplastic shield in
position.
A further feature of the invention provides wedging surfaces on said
retaining clip portions, to facilitate spreading of said retaining
portions, for attachment to said metal panels.
A further feature of the invention provides for openings through said panel
portions and through said thermoplastic shield.
A further feature of the invention provides a wrap around plastic shield,
which is adhesively or chemically bonded to the metal clip.
A further feature of the invention provides a two part construction of the
plastic shield, and in some cases provides for bonding of the two parts
together around the clip, either adhesively, chemically, or by ultra-sonic
welding techniques.
The invention also provides a method of making such furniture clips
incorporating a plastic shield.
The various features of novelty which characterize the invention are
pointed out with more particularity in the claims annexed to and forming a
part of this disclosure. For a better understanding of the invention, its
operating advantages and specific objects attained by its use, reference
should be had to the accompanying drawings and descriptive matter in which
there are illustrated and described preferred embodiments of the invention
.
IN THE DRAWINGS
FIG. 1 is a perspective illustration of a typical apparatus for
manufacturing furniture clips in accordance with this embodiment of the
invention;
FIG. 2 is a section along the line 2--2 of FIG. 1;
FIG. 3 is a section along the line 3--3 of FIG. 1;
FIG. 4 is a section along the line 4--4 of FIG. 1;
FIG. 5 is a perspective illustration showing a furniture clip illustrating
an embodiment of the invention;
FIG. 6 is a perspective of an alternate embodiment of the invention;
FIG. 7 is a further perspective of a further alternate embodiment of the
invention;
FIG. 8 is a section along the line 8--8 of FIG. 6;
FIG. 9 is a section along the line 9--9 of FIG. 7;
FIG. 10 is a section of a further embodiment;
FIG. 11 is a section of a clip shown installed;
FIGS. 12, 13, 14, and 15, are sections of further embodiments;
FIGS. 16a and 16b are sections of a further embodiment showing two stages
in its formation;
FIG. 17 is a section of a further embodiment;
FIG. 18 is a section of a clip installed, corresponding to the clips of
FIGS. 12 to 17, and,
FIG. 19 is a schematic perspective of the method of manufacture of clips
shown in FIGS. 12 to 17.
DESCRIPTION OF A SPECIFIC EMBODIMENT
As explained above, the invention relates to furniture clips of the type
which ate used for retaining wire spring assemblies on furniture.
Although not illustrated, it is well known that around the edge of each the
wire spring assemblies the furniture clips engage the wire and secure it
to the solid frame of the piece of furniture.
As already explained where the wire of the spring assembly contacts the
furniture clip, there is a substantial amount of metal to metal friction.
When the wire twists within the clip, it will typically create frictional
sounds. It is appreciated of course that there are a large number of such
furniture clips attaching each wire assembly to the frame, so that there
are in fact a large number points within a furniture spring assembly, at
which such metal to metal friction will occur.
Referring first of all to FIG. 5, it will be seen that an embodiment of the
invention is illustrated there, in the form of composite furniture clip
indicated generally as 10. The clips 10 comprises two panels of sheet
metal 12 and 14, meeting one another and integrally formed around a curve
16. Openings 18 of elongated shape, arranged in pairs parallel with one
another, in respective panel portions 12 and 14, and arranged so the the
openings in panel 12 register with the openings in panel 14 are provided
for passing fastenings into a frame work or furniture structure. The
curved portion 16 of the panels, establishes a recess for engaging and
grasping the wire edge frame (not shown) of a typical furniture spring
assembly.
In accordance with the invention, it will also be seen that the two panels
12 and 14 define between them an acute angle, and define inwardly facing
surfaces 20--20 and outwardly facing surfaces 22--22.
In accordance with the invention, and in order to reduce or restrict the
frictional sounds or noise created by movement of the wire spring in the
clip, each clip is provided with a thermoplastic shield 24. Each
thermoplastic shield in this embodiment will be seen to comprise a central
generally planar shield portion 26, and edge formations 28--28 along
either side thereof.
Openings 30 of elongated shape arranged in pairs parallel with one another.
Openings 30 are formed through the planar portions of the shield portion
26 overlying both panels 12 and 14 so that they register with the openings
18 both panels 12 and 14 of the clip so as to provide clear openings
through both the clip and the shield portions.
Each of the edge formations 28 of the thermoplastic shield 24 in this
embodiment include generally bevelled corners 32, side edge portions 34,
and retaining clip portions 36. The retaining clip portions are adapted to
engage the edge surfaces of the metal panels 12, 14 and retain the shield
in position. Each of the retaining clip portions 36 is formed with a
wedging surface 38, the purposes which will be described below.
It will thus be seen that by this embodiment of the invention, the recess
portion of the clip which engages the wire spring (not shown) is
completely protected and shielded by thermoplastic. In addition, the edge
portions of the recess where the wire frame would enter and exit the
recess are buttressed and reinforced with the shielding edge portions 28
of the thermoplastic shield. All of this has the effect of substantially
reducing the tendency for friction and friction sounds when there is
movement between the spring frame and the furniture clips.
At the same time, the exterior or outwardly facing surfaces of the
furniture clip are not themselves shielded. This produces a significant
saving in thermoplastic material. In addition, however, as will be
explained below by the use of a thermoplastic shield of this shape, having
edges, it is possible to make the shield a secure fit on the metal panels
at the locations especially on the edges, where the metal to metal
pressure, and hence friction, would otherwise be the greatest.
The method of manufacture of such furniture clips will now be described
with reference to FIGS. 1, 2, 3, and 4.
As shown schematically in FIG. 1, one form of apparatus on which the clips
may be formed is indicated generally as 40.
This apparatus consists of a base plate 42 supported by any suitable means
(not shown), and defining a feed end 44 and output end 46. At the feed end
44 there is a strip metal feed unit 48, for feeding strip metal M along
the base plate. In addition, there is a thermoplastic feed unit 50, for
feeding the thermoplastic shield material T to the base plate 42. A
junction station 52 is provided along the base plate 42, for joining the
thermoplastic shield material to the sip metal. A stamping and cut-off die
unit 54 is provided at the delivery end 46 of the base plate 42 for
cutting off and forming the clips. Where adhesive or other bonding is used
between the clip and the shield, a dispensing nozzle 55 is provided, being
located so as to dispense an adhesive, or a chemical bonding agent,
between the metal strip M and the plastic strip T. The nozzle is
positioned just upstream of the section line 2--2, where there is adequate
space between the two strips.
A bin 56 is located beneath the press to collect finished clips.
FIG. 1 illustrates three sections indicated as 2, 3, and 4, indicating
successive stages in the assembly of the thermoplastic shield material
with the strip sheet metal.
At the location of FIG. 2, the strip sheet metal is indicated as M and the
thermoplastic shield material is indicated as T. At this stage, both
materials are essentially continuous strips of such material, being fed
separately. The indication of two feed roll units is purely schematic. The
material can equally well be fed in linear lengths, in any well known
manner.
At this location, the two strips are maintained spaced apart but in
vertical registration with one another.
At the joining station 52 (FIG. 3), the two strips M and T are brought
together, and pressure is applied to the thermoplastic shield strip
forcing it downwardly against the sheet metal strip. In the cases where
some kind of adhesive is being used, this pressure will assist in
achieving a secure bond.
In the case of the FIG. 2, 3 and 4 embodiment, the pressure has the effect
of causing the wedging surfaces 38 to spread apart to wrap around the
edges of the sheet metal strip.
Once the two strips exit from the station 52 (FIG. 4), the thermoplastic
shield strip is snugly interfitted around the edges of the sheet metal
strip as shown in FIG. 4. At the stamping and cutting station 54, an end
portion of the two strips is cut off and openings are punched through the
two strips simultaneously, and the bend is then formed, forming the
finished bent over Clip as shown in FIG. 5.
Referring to FIG. 6, an alternate embodiment of the invention is shown
which comprises a metal clip 60--60, being formed essentially in the same
way as the panels 12 and 14 of FIG. 5.
A generally channel-shaped thermoplastic shield 62 is attached to the
inwardly facing surfaces of the clip 60--60. The thermoplastic shield 62
has side wall formations 64--64 which extend around both side edges of the
clip 60.
The shield will typically be adhesively or chemically bonded to the metal
of the clip as indicated at A in FIG. 6. Such bonding may be used in all
embodiments.
The section of FIG. 8 relates to the FIG. 6 embodiment.
A further alternate embodiment of the invention is shown in FIG. 7. In this
case a clip 70 having edges 72--72 is provided with a thermoplastic shield
74, positioned over the inwardly facing surfaces of the clip. The shield
74 has inwardly angled generally wedge shaped edge formation 76--76,
adapted to snap fit around the edges 72 of the clip 70.
The section of FIG. 9 relates to the embodiment of FIG. 7.
The further embodiment is shown in section in FIG. 10. In this case the
sheet metal strip has a plastic shield 82, with edge formations 84--84.
The edge formations 84 are bulged outwardly so as to provide still greater
useful life to the plastic shield.
FIG. 11 illustrates the use of a furniture clip in accordance with the
invention when installed on an article of furniture shown as F.
As previously explained, a wire N of a furniture spring assembly is
captured in the furniture clip. The fastener N is then inserted through
the openings and driven into the furniture F. In doing so it bends the
furniture clip around the wire W into the shape as shown in section.
In FIG. 11, the furniture clip is represented generally as 100, with the
metal strip being the outer portion indicated as 102, and the
thermoplastic shield being the inner portion and indicated as 104.
Further embodiments are illustrated in FIGS. 12, 13, and 14.
In FIG. 12 a metal strip 110 is completely encased in a pair of generally
U-shaped thermoplastic shields 112--112. Typically the shields would be
bonded to the metal strip adhesively or by chemical means.
In FIG. 13 the strip 114 is encased by two U-shaped members 116. In this
case, the U-shaped members 116 may be bonded together where they abut at
118, e.g. adhesively, chemically or ultrasonically.
In FIG. 14, the sheet metal member is again encased in two U-shaped members
120. However, on one side at least the members are provided with an angled
or scarfed joint 112. This could be joined and bonded by chemical means or
by heat and pressure, or ultrasonic welding.
FIG. 15 illustrates a slight modification in that the sheet metal 112 has
two thermoplastic shield portions 126 which are of J-shape in section. The
two longer J portion extend completely over the one side of the metal
strip 124. The shorter portions wrap around the edges and overlap the
other side. Typically in this example the two portions would be adhesively
bonded to the metal strip.
Still another version is shown in FIGS. 16A and 16B. In this case a metal
strip 128 has a thermoplastic shield 130, which is of one piece integral
construction. In a multi-stage process, heat would be applied, and the
shield 130 would then be bent upwardly and inwardly as at 132--132 to wrap
around the reverse side of the metal strip 128. Again, typically there
would be some form of adhesive or chemical bonding.
FIG. 17 illustrates a still further embodiment. This is somewhat similar to
the embodiment of FIG. 15 in that the sheet metal strip 134 has two
generally J-shaped portions 136 and 138 wrapping around the one side of
the strip and around the two edges.
However, the thermoplastic members are formed with reduced thickness
portions 140 and 142, which would overlap and provide a region for
chemical or heat and pressure bonding, or ultrasonic welding.
This version would have certain advantages. It reduces the volume of
plastic, It improves the process for punching the openings.
FIG. 18 represents the use of the clip on a piece of wire spring,
incorporated in a piece of furniture. In this case, the clip represents
any one of FIGS. 12 through 17.
It will be seen that the clip C, comprises a metal strip M, provided with
an inner thermal plastic shield S, and around the exterior, the wrap
around edges of the shield S are shown as E. A fastening N secures the
clip to the furniture F.
The method of manufacturing the clips of FIGS. 12, 13, 14, 15, and 17, is
illustrated generally in FIG. 19.
In this case, since there will be two separate strips of thermoplastic
strips T, there are two storage rolls 150-152, storing respective
thermoplastic strips T1 and T2. They are spaced apart from one another,
and would supply the plastic in either elongated U-shaped form or J-shaped
form, on opposite sides of the metal strip H, which strip is supplied by
roll 154. At the station 156, the two thermoplastic strips T1 and T2 would
be squeezed on to the edges of the strip M from either side. Any suitable
bonding agent could be supplied from nozzle 158. Alternatively, if
ultrasonic welding were used, then the welding could be effected by means
such as the ultrasonic welding unit 160.
The embodiment of FIG. 16A and 16B would require a minor modification of
the FIG. 1 method so as to apply heat to the thermoplastic strip, and to
bend the two side edges as shown in FIG. 16A, such modifications being
apparent to those skilled in the art.
The foregoing is a description of a preferred embodiment of the invention
which is given here by way of example only. The invention is not to be
taken as limited to any of the specific features as described, but
comprehends all such variations thereof as come within the scope of the
appended claims.
Top